Displaying a local webpage

I can't figure out how to display a local webpage. I've tried messing with the webBrowser control but it keeps adding "http://" to the front of the local webpage address, and if I try to change it from within the code like this:

webBrowser1.Url = "file:\\webpage\Maphs v1.htm";

I get the following error:error CS1009: Unrecognized escape sequence

Can anyone help me out? The page I want to display is just one page, and it is stored locally in the same folder as the program.

ddanbe: I tried "webBrowser1.Navigate(webpage/Maphs v1.htm)", that gave me a 404.

LizR:
The HTML file is in a directory called "webpage", which is in the same directory as the program.

I wanted a local reference to the file, so that if I wanted to move the program's directory, it would work anyway. Evidently, that didn't happen.
Is there a way to make a local reference like that? Or should I just give up and hardcode the path in (which works)?